Liquid cooled dynamoelectric machine for absorbing energy



Oct. 7, 1947. L. D. NORDSTRUM LIQUID COOLED DYNAMOELECTRIC MACHINE FOR ABSORBING ENERGY Original Filed Oct. 26, 1945 2 Sheets-Sheet 1 Deceased, strum Inventor .Nord u ude 0 J6! 2d; in iszratrix, b 7

JHis ttorneg.

Patented Oct. 7, 1947 LIQUID COOLED DYNAMOELECTRIC MA CHINE FOR ABSOBBING ENERGY Lauren D. Nordstrum, deceased, late of' Fort Wayne, Ind., by Gertrude 0. Nordatrum, administratrlx, Fort Wayne, 1nd.; said administratrix aasignor to General Electric Company, a corporation of New York Continuation oi application Serial No. 507,707,

October 26,

1943. This application died June 13, 1945, Serial No. 599,188

6 Claims. (Cl; 188-104) This invention relates to dynamoelectric machines and particularly to eddy current induction dynamometers which are adapted to be cooled by liquid.

This application is a continuation of the copending forfeited application Serial No. 507,707, on Dynamoelectric machine, flied October 26, 1943, and assigned to the assignee of this appli-v cation.

An object of this invention is to provide an improved dynamoelectric machine which is cooled by the circulation of cooling liquid directly in contact with surfaces of the relatively rotatable members of the machine.

Another object of this invention is to provide an improved eddy current dynamoelectric machine with a liquid cooling system adapted to circulate cooling liquid in contact with the eddycurrent surfaces of the machine.

Further objects and advantages of this invention will become apparent and the invention will be better understood from the following description referring to the accompanying drawings, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of this specification,

In the drawings, Fig. l is a side elevation view, partly in section, illustrating an eddy current induction dynamometer provided with an embodiment of "the invention; Fig. 2 is an end view, partly broken away, of the machine shown in Fig. 1; Fig. 3 is a sectional side elevational view of a part of a machine embodying a modification of the arrangement shown in Fig. 1; Fig. 4 is a fragmentary partial sectional end view showing the cooling liquid supply arrangement incorporated in the machine illustrated in Fig. 3; Fig. 5 is a side elevational view, partly in section, illustrating a dynamoelectric machine embodying a further modification of the invention; and Fig. 6 is an end view of the machine shown in Fig. 5, partly broken away.

Referring to the drawing, an embodiment of the invention is shown adapted to an eddy current induction dynamometerof the absorption type provided with two relatively rotatable members. one of which is relatively stationary and includes two similar half portions l0 formed 0! magnetic material and secured together by a plurality of circumferentlally spaced apart through bolts I I. These members I! are each formed with a pair of radially spaced apart toothed sections having a plurality of teeth i2 and II which are circumferentlally spaced apart on the inner side of the machine. The radial relationship of these two sets of teeth provides a space between which an eddy current member is adapted to rotate. This memberis formed as the other relatively rotatable member of the machine and includes a spider and hub portion it with an axially extending relatively thin flange ll formed about the outer edge thereof which extends between the toothed portions l2 and II. This member is mounted on a shaft II which may be made of non-magnetic material to prevent shunting oi the flux around the air gap between the teeth It and I3, and this shaft is supported by anti-friction ball bearings ll mounted in a bearing housing It formed in the end shields is which support the other relatively rotatable members. The bearing housings it are rotatably supported by antifriction ball bearings 20 in bearing housings 21 formed in pedestals 22 arranged at each end of the machine so as to rotatably support the entire machine. A fleld exciting winding 23 is mounted about the flange portion II of the inner member and is arranged between the two sections Ill of 25 the relatively stationary member. This winding is adapted to provide magnetic excitation to both relatively rotatable members, such that when the shaft i8 is driven, the flange portion II will rotate between the teeth I! and i3 and cut the magnetic flux passing between these parts of the toothed member into the flange II from one side of the machine to these same respective elements on the other side of the machine, thereby generating eddy currents in the flange portion I5 and absorbing energy in the form of heat in this member. Cooling liquid, such as water, is adapted to be supplied to the interior. or the machine through a flexible pipe connection 24, and this cooling liquid is adapted to be circulated over and through the flange member II and to be drained from the casing through exhaust pipe connections 25 at the lower portion of the machine. In order to assist the circulation of the cooling liquid and to provide more intimate contact between the cooling liquid and the flange portion it, a plurality of outwardly extending passages 28 are formed through the flange portion It. This makes the flange portion it in effect an impeller member and creates a higher liquid pressure on the outside of this member in the air gap between the teeth l2 and the flange portion l5. Circulation of the cooling liquid also is increased by providing a recirculating liquid connection 21 which extends from adJacent the outer edge of 3 the. flange member I! near the air gap to the cooling liquid supply connection 24, such that the pressure within the machine adjacent the outer edge of the flange portion l5 causes the flow of cooling liquid through the connection 21 into the inlet connection 24 and assists in forcing this liquid into the interior of the machine. Sealing glands 28 are arranged adjacent each end of the relatively stationary member and are formed with labyrinth sealing portions 28 to minimize the passage of cooling liquid outwardly along the shaft from the interior of the machine. These sealing glands preferably are formed of nonmagnetic material in order to minimize the shunting of the flux as much as possible through these glands and the shaft it. This provides an efiicient cooling system for an eddy current induction type machine, since the cooling liquid is brought into direct contact with the heated surface, thereby providing for a relatively quick transfer of the generated heat into the cooling medium, and only a relatively small cooling liquid pressure is required to inject the cooling liquid into the machine because of the improved recirculating injector action or the connection 21 together with the impeller construction of the eddy current flangeportion ii.

In Figs. 3 and 4, another modification of the invention is shown in which the same basic elements as those shown in Fig. 1 are provided, although the cooling system is slightly different. In this arrangement, the machine is provided with cooling liquid supply connections 29 which supply cooling liquid to passageways 30 formed in the relatively stationary member, and this cooling liquid is injected into the air gap between the'relatively rotatable members through axially extending grooves 3| formed in the interior surfaces of the teeth I Z so as to supplythe cooling medium directly onto the outer smooth eddy current surface of the relatively thin flange portion IS. The same recirculating injector connection 21 as that used in Fig. 1 may also be utilized in this construction to increase the efliciency of the cooling system.

In Figs. 5 and 6 another embodiment of the improved machine is shown in which two relatively rotatable members are provided, one of which is relatively stationary and includes an annular central member 32 formed of magnetic material and provided with two sets of axially spaced apart toothed portions 33 formed with circumferentially spaced apart teeth and securely connected to end members 34 formed of magnetic material and having a plurality of circumferentially spaced apart teeth 35 spaced radially from the toothed portions 33. The other relatively rotatable member also is formed of magnetic material and is provided with a web and hub portion 36 and an outer double flange portion 31' which extends between the toothed portions 33 and 35 of the other relatively rotatable member. The surfaces of the flange portion 31 adjacent the toothed portions 33 and 35 are faced with a material of relatively low resistance in the form of copper plates 38 and 39 having relatively smooth surfaces and secured to the cylindrical surfaces of the flange portion 31 in any suitable manner, as by screws 40. An exciting winding 4| is held-in position on each side of the machine by plates 45 to provide magnetic excitation to both relatively rotatable members of the machine such that the magnetic flux tends to pass from the toothed portion 33, through the flange portion 31, to the toothed portion 35 and around through 4 the body portions 34 and 32, such that rotation of the flange portion 31 between the toothed portions generates relatively high eddy currents in the low resistance elements 33 and 33. These eddy curernts absorb energy and transform this energy into heat losses tending to raise the temperature of the flange portion 31. Efiicient operation of the machine is obtained by cooling this member with a cooling liquid supplied to the interior of the machine by a suitable flexible connection 42 and circulating this cooling liquid through the air gaps over the eddy current elements 38 and 39 and through the supporting flange portion by providing outwardly extending passages 43 through the flange portion 31, so that this part of the machine is in effect a liquid impeller which circulates the liquid through the machine. The warmed cooling liquid is removed from the machine through a suitable drain connection 44. The relatively rotatable parts of the machine are rotatably supported adjacent each end thereof by suitable bearing constructions such as those disclosed in Fig. 1.

While there are illustrated and described particular embodiments of the invention, modifications thereof will occur to those skilled in the art. It should be understood, therefore, that the invention is not to be limited to the particular arrangements disclosed, and it is intended in the appended claims to cover all modifications which do not depart from the spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States, is:

1. An induction dynamoelectric machine having two relatively rotatable members, one of said members having a portion formed of magnetic material with toothed sections having a plurality of teeth extending toward the other of said members, the other of said members having a section of magnetic material and a relatively smooth eddy current surface portion arranged adjacent said toothed sections with air gaps therebetween, means including a fleld exciting winding for magnetically exciting both of said members, means for supplying cooling liquid to the interior of said machine, said other member being constructed and arranged to circulate said cooling liquid through said air gap, and means for recirculating cooling liquid from said air gap to said cooling liquid supply means for increasing the circulation of the liquid.

2. An eddy current induction dynamoelectric machine having two relatively rotatable members, one of said members having a portion formed of magnetic material with toothed sections having a plurality of teeth extending toward the other of said members, the other of said members having a section of magnetic material and a relatively smooth eddy current surface portion of relatively low resistance material formed as a relatively thin flange arranged adjacent said toothed sections with air gaps therebetween, means including a fleld exciting winding for magnetically exciting both of said members, and means for supplying cooling liquid to the interior of said machine, said other member being constructed as an impeller for circulating said cooling liquid through said air gap in contact with said eddy current surface.

3. .An eddy current induction dynamoelectric' machine having two relatively rotatable members,- one 01' said members having a portion formed of magnetic material with radially spaced apart toothed sections having a plurality of teeth extending toward the other of said members, the other of said members having a section of magnetic material formed as a relatively thin flange arranged between and adjacent said toothed sections with air gaps th'erebetween, means including a fleld exciting winding for magnetically exciting both 'of said members, means for supplying cooling liquid to the interior of said machine, said other member being constructed as an impeller for circulating said cooling liquid through said air gap and over said flange, and means for recirculating cooling liquid from said air gap to said cooling liquid supply means for increasing the circulation of the liquid.

4. An induction dynamoelectric machine having two relatively rotatable members, one of said members having a portion formed 01 magnetic material with toothed sections having a plurality of teeth extending toward the other or said members, the other of said members having a section of magnetic material and a relatively smooth eddy current surface portion formed as a relatively thin flange arranged between and adjacent said toothed sections with air gaps therebe-:- tween, means including a field exciting winding ior magnetically exciting both of said members, means for supplying cooling liquid to the interior of said machine, said other member being constructed as an impeller for circulating said cool ing liquid through said air gap, and means for recirculating cooling liquid from said air gap to said cooling liquid supply means for increasing the circulation of the liquid.

5. An eddy current induction dynamoelectric machine having two relatively rotatable members, one or said members having a portion formed or magnetic material with a toothed section having a plurality of teeth extending toward the other of said members, the other of said members having a section of magnetic material and a relatively smooth eddy current surface portion arranged adjacent said toothed section with an,

air gap therebetween, means including a fleld exciting winding for magnetically exciting both or said members, means for supp ying cooling liquid to the interior of said machine, said other member being constructed and arranged to cir- 6 culate said cooling liquid through said air gap, and means for recirculating cooling liquid from said air gap to said cooling liquid supply means for increasing the circulation of the liquid.

6. An eddy current induction dynamoelectric machine having two relatively rotatable members, one of said members having a portion formed of magnetic material with toothed sections having a plurality of teeth extending toward the other of said members, the other 01 said members having a section of magnetic material formed as a relatively thin flange arranged between and adjacent said toothed sections with air gaps therebetween, means including a relatively thin smooth surface element on each side of said flange formed of relatively low resistance material for the generation of high eddy currents therein, means including a fleld exciting winding for magnetically exciting both or said members, mean for supplying cooling liquid to the interior of said machine, said other member being constructed as an impeller for circulating said cooling liquid through said air gap and over said low resistance element for cooling said elements, and means ior recirculating cooling liquid from said air gap to said cooling liquid supply means for increasing the circulation of the liquid.

GERTRUDE O. NORDS'I'RUM, Administratria: of the' Estate of Lauren D.

Nordstrum, Deceased.

REFERENCES CITED The following references are 01' record in the me of this patent:

UNITED STATES PATENTS Number Name Date 2,367,163 Winther Jan. 9, 1945 2,188,398 Bernard Jan. 30, 1940 1,779,797 Baum Oct. 28, 1930 1,691,696 Baum Nov. 13, 1928 FOREIGN PATENTS Number Country Date 418,443 Great Britain Oct. 22, 1934 

